A serum ketones test determines the levels of ketones in your blood. Ketones are a byproduct produced when your body uses only fat, instead of glucose, for energy.
When ketones accumulate in the blood, the body enters ketosis. For some people, ketosis is normal. Low-carbohydrate diets can induce this state. This is sometimes called nutritional ketosis.
Doctors use serum ketone tests primarily for screening DKA, but they may order them to diagnose alcoholic ketoacidosis or starvation as well. Pregnant women with diabetes will often take the urine ketone test if their meters aren’t able to read blood ketone levels to track ketones frequently. The serum ketone test, also known as the blood ketone test, looks at how much ketone is in your blood at the time. Your doctor can test for the three known ketone bodies separately. They include:
A serum ketone test is done in a laboratory setting using a sample of your blood. Your doctor will tell you if you need to prepare and how to prepare if you do. A healthcare provider will use a long, thin needle to draw several small vials of blood from your arm. They’ll send the samples to a lab for testing. After the blood draw, your doctor will place a bandage over the injection site. This can be taken off after an hour. The spot may feel tender or sore afterward, but this typically goes away by the end of the day.
When your test results are available, your doctor will review them with you. This may be over the phone or at a follow-up appointment. If the serum ketone readings are 1.5 or less, the value is normal. If it is between 1.6 and 3.0, you have to check again within two to four hours. If it is over 3.0, you have to go to the ER immediately.